The major distinctive feature of USB 3.0 connectors is that they are typically blue in color internally while USB 2.0 connectors tend to be back or white. This can be seen in our chart below.

For USB 2.0 there are several versions of Mini/Micro that are similar in size and number of pins. The most common of these are USB Mini-B 5 pin and USB Micro-B. The main visual difference between these two connectors is in the sides of these connectors. The Mini-B connector features a stepped design while the Micro USB edge is straight.